diff --git a/src/printer.js b/src/printer.js
index de92d7510..f62728040 100644
--- a/src/printer.js
+++ b/src/printer.js
@@ -3917,8 +3917,15 @@ function makeString(rawContent, enclosingQuote) {
       return "\\" + quote;
     }
 
-    // Otherwise return the escape or unescaped quote as-is.
-    return match;
+    if (quote) {
+      return quote;
+    }
+
+    // Unescape any unnecessarily escaped character.
+    // Adapted from https://github.com/eslint/eslint/blob/de0b4ad7bd820ade41b1f606008bea68683dc11a/lib/rules/no-useless-escape.js#L27
+    return /^[^\\nrvtbfux\r\n\u2028\u2029"'0-7]$/.test(escaped)
+      ? escaped
+      : "\\" + escaped;
   });
 
   return enclosingQuote + newContent + enclosingQuote;
diff --git a/tests/directives/__snapshots__/jsfmt.spec.js.snap b/tests/directives/__snapshots__/jsfmt.spec.js.snap
index b7e1f0373..342de6894 100644
--- a/tests/directives/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/directives/__snapshots__/jsfmt.spec.js.snap
@@ -1,19 +1,77 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`escaped.js 1`] = `
+// Unnecessary escapes. (adapted from tests/quotes/strings.js)
+// Note that in directives, unnecessary escapes should be preserved.
+// See https://github.com/prettier/prettier/issues/1555
 '\\'';
 '\\"';
 "\\'";
 "\\"";
 '\\\\';
 '\\a';
+"hol\\a"
+'hol\\a'
+"hol\\\\a (the a is not escaped)"
+'hol\\\\a (the a is not escaped)'
+"multiple \\a unnecessary \\a escapes"
+'multiple \\a unnecessary \\a escapes'
+"unnecessarily escaped character preceded by escaped backslash \\\\\\a"
+'unnecessarily escaped character preceded by escaped backslash \\\\\\a'
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a"
+'unescaped character preceded by two escaped backslashes       \\\\\\\\a'
+"\\a\\a" // consecutive unnecessarily escaped characters
+'\\a\\a' // consecutive unnecessarily escaped characters
+'escaped \\u2030 \\‰ (should still stay escaped)'
+
+// Meaningful escapes
+// Commented out to avoid \`SyntaxError: Octal literals are not allowed in strict mode.\`
+// "octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7"
+// 'octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7'
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61"
+'meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61'
+'escaped newline \\
+'
+'escaped carriage return \\
+'
+'escaped \\u2028 \\
'
+'escaped \\u2029 \\
'
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// Unnecessary escapes. (adapted from tests/quotes/strings.js)
+// Note that in directives, unnecessary escapes should be preserved.
+// See https://github.com/prettier/prettier/issues/1555
 '\\'';
 '\\"';
 "\\'";
 "\\"";
 "\\\\";
 "\\a";
+"hol\\a";
+"hol\\a";
+"hol\\\\a (the a is not escaped)";
+"hol\\\\a (the a is not escaped)";
+"multiple \\a unnecessary \\a escapes";
+"multiple \\a unnecessary \\a escapes";
+"unnecessarily escaped character preceded by escaped backslash \\\\\\a";
+"unnecessarily escaped character preceded by escaped backslash \\\\\\a";
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a";
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a";
+"\\a\\a"; // consecutive unnecessarily escaped characters
+"\\a\\a"; // consecutive unnecessarily escaped characters
+"escaped \\u2030 \\‰ (should still stay escaped)";
+
+// Meaningful escapes
+// Commented out to avoid \`SyntaxError: Octal literals are not allowed in strict mode.\`
+// "octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7"
+// 'octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7'
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61";
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61";
+"escaped newline \\
+";
+"escaped carriage return \\
+";
+"escaped \\u2028 \\
";
+"escaped \\u2029 \\
";
 
 `;
 
diff --git a/tests/directives/escaped.js b/tests/directives/escaped.js
index 67fb803fb..8894f70a6 100644
--- a/tests/directives/escaped.js
+++ b/tests/directives/escaped.js
@@ -1,6 +1,35 @@
+// Unnecessary escapes. (adapted from tests/quotes/strings.js)
+// Note that in directives, unnecessary escapes should be preserved.
+// See https://github.com/prettier/prettier/issues/1555
 '\'';
 '\"';
 "\'";
 "\"";
 '\\';
 '\a';
+"hol\a"
+'hol\a'
+"hol\\a (the a is not escaped)"
+'hol\\a (the a is not escaped)'
+"multiple \a unnecessary \a escapes"
+'multiple \a unnecessary \a escapes'
+"unnecessarily escaped character preceded by escaped backslash \\\a"
+'unnecessarily escaped character preceded by escaped backslash \\\a'
+"unescaped character preceded by two escaped backslashes       \\\\a"
+'unescaped character preceded by two escaped backslashes       \\\\a'
+"\a\a" // consecutive unnecessarily escaped characters
+'\a\a' // consecutive unnecessarily escaped characters
+'escaped \u2030 \‰ (should still stay escaped)'
+
+// Meaningful escapes
+// Commented out to avoid `SyntaxError: Octal literals are not allowed in strict mode.`
+// "octal escapes \0 \1 \2 \3 \4 \5 \6 \7"
+// 'octal escapes \0 \1 \2 \3 \4 \5 \6 \7'
+"meaningfully escaped alphabetical characters \n \r \v \t \b \f \u2713 \x61"
+'meaningfully escaped alphabetical characters \n \r \v \t \b \f \u2713 \x61'
+'escaped newline \
+'
+'escaped carriage return \
+'
+'escaped \u2028 \
'
+'escaped \u2029 \
'
diff --git a/tests/quotes/__snapshots__/jsfmt.spec.js.snap b/tests/quotes/__snapshots__/jsfmt.spec.js.snap
index f5ead8960..558c9e1e4 100644
--- a/tests/quotes/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/quotes/__snapshots__/jsfmt.spec.js.snap
@@ -68,6 +68,33 @@ exports[`strings.js 1`] = `
 // Unnecessary escapes.
 "\\'"
 '\\"'
+"\\a"
+'\\a'
+"hol\\a"
+'hol\\a'
+"hol\\\\a (the a is not escaped)"
+'hol\\\\a (the a is not escaped)'
+"multiple \\a unnecessary \\a escapes"
+'multiple \\a unnecessary \\a escapes'
+"unnecessarily escaped character preceded by escaped backslash \\\\\\a"
+'unnecessarily escaped character preceded by escaped backslash \\\\\\a'
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a"
+'unescaped character preceded by two escaped backslashes       \\\\\\\\a'
+"\\a\\a" // consecutive unnecessarily escaped characters
+'\\a\\a' // consecutive unnecessarily escaped characters
+'escaped \\u2030 \\‰ (should not stay escaped)'
+
+// Meaningful escapes
+"octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7"
+'octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7'
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61"
+'meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61'
+'escaped newline \\
+'
+'escaped carriage return \\
+'
+'escaped \\u2028 \\
'
+'escaped \\u2029 \\
'
 
 // One of each.
 "\\"'"
@@ -138,6 +165,32 @@ exports[`strings.js 1`] = `
 // Unnecessary escapes.
 "'";
 '"';
+"a";
+"a";
+"hola";
+"hola";
+"hol\\\\a (the a is not escaped)";
+"hol\\\\a (the a is not escaped)";
+"multiple a unnecessary a escapes";
+"multiple a unnecessary a escapes";
+"unnecessarily escaped character preceded by escaped backslash \\\\a";
+"unnecessarily escaped character preceded by escaped backslash \\\\a";
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a";
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a";
+"aa"; // consecutive unnecessarily escaped characters
+"aa"; // consecutive unnecessarily escaped characters
+"escaped \\u2030 ‰ (should not stay escaped)";
+// Meaningful escapes
+"octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7";
+"octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7";
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61";
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61";
+"escaped newline \\
+";
+"escaped carriage return \\
+";
+"escaped \\u2028 \\
";
+"escaped \\u2029 \\
";
 // One of each.
 "\\"'";
 "\\"'";
@@ -206,6 +259,33 @@ exports[`strings.js 2`] = `
 // Unnecessary escapes.
 "\\'"
 '\\"'
+"\\a"
+'\\a'
+"hol\\a"
+'hol\\a'
+"hol\\\\a (the a is not escaped)"
+'hol\\\\a (the a is not escaped)'
+"multiple \\a unnecessary \\a escapes"
+'multiple \\a unnecessary \\a escapes'
+"unnecessarily escaped character preceded by escaped backslash \\\\\\a"
+'unnecessarily escaped character preceded by escaped backslash \\\\\\a'
+"unescaped character preceded by two escaped backslashes       \\\\\\\\a"
+'unescaped character preceded by two escaped backslashes       \\\\\\\\a'
+"\\a\\a" // consecutive unnecessarily escaped characters
+'\\a\\a' // consecutive unnecessarily escaped characters
+'escaped \\u2030 \\‰ (should not stay escaped)'
+
+// Meaningful escapes
+"octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7"
+'octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7'
+"meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61"
+'meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61'
+'escaped newline \\
+'
+'escaped carriage return \\
+'
+'escaped \\u2028 \\
'
+'escaped \\u2029 \\
'
 
 // One of each.
 "\\"'"
@@ -276,6 +356,32 @@ exports[`strings.js 2`] = `
 // Unnecessary escapes.
 "'";
 '"';
+'a';
+'a';
+'hola';
+'hola';
+'hol\\\\a (the a is not escaped)';
+'hol\\\\a (the a is not escaped)';
+'multiple a unnecessary a escapes';
+'multiple a unnecessary a escapes';
+'unnecessarily escaped character preceded by escaped backslash \\\\a';
+'unnecessarily escaped character preceded by escaped backslash \\\\a';
+'unescaped character preceded by two escaped backslashes       \\\\\\\\a';
+'unescaped character preceded by two escaped backslashes       \\\\\\\\a';
+'aa'; // consecutive unnecessarily escaped characters
+'aa'; // consecutive unnecessarily escaped characters
+'escaped \\u2030 ‰ (should not stay escaped)';
+// Meaningful escapes
+'octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7';
+'octal escapes \\0 \\1 \\2 \\3 \\4 \\5 \\6 \\7';
+'meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61';
+'meaningfully escaped alphabetical characters \\n \\r \\v \\t \\b \\f \\u2713 \\x61';
+'escaped newline \\
+';
+'escaped carriage return \\
+';
+'escaped \\u2028 \\
';
+'escaped \\u2029 \\
';
 // One of each.
 '"\\'';
 '"\\'';
diff --git a/tests/quotes/strings.js b/tests/quotes/strings.js
index 163724232..34c5b921e 100644
--- a/tests/quotes/strings.js
+++ b/tests/quotes/strings.js
@@ -35,6 +35,33 @@
 // Unnecessary escapes.
 "\'"
 '\"'
+"\a"
+'\a'
+"hol\a"
+'hol\a'
+"hol\\a (the a is not escaped)"
+'hol\\a (the a is not escaped)'
+"multiple \a unnecessary \a escapes"
+'multiple \a unnecessary \a escapes'
+"unnecessarily escaped character preceded by escaped backslash \\\a"
+'unnecessarily escaped character preceded by escaped backslash \\\a'
+"unescaped character preceded by two escaped backslashes       \\\\a"
+'unescaped character preceded by two escaped backslashes       \\\\a'
+"\a\a" // consecutive unnecessarily escaped characters
+'\a\a' // consecutive unnecessarily escaped characters
+'escaped \u2030 \‰ (should not stay escaped)'
+
+// Meaningful escapes
+"octal escapes \0 \1 \2 \3 \4 \5 \6 \7"
+'octal escapes \0 \1 \2 \3 \4 \5 \6 \7'
+"meaningfully escaped alphabetical characters \n \r \v \t \b \f \u2713 \x61"
+'meaningfully escaped alphabetical characters \n \r \v \t \b \f \u2713 \x61'
+'escaped newline \
+'
+'escaped carriage return \
+'
+'escaped \u2028 \
'
+'escaped \u2029 \
'
 
 // One of each.
 "\"'"