diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsArrayToPointerDecayCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsArrayToPointerDecayCheck.cpp
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsArrayToPointerDecayCheck.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsArrayToPointerDecayCheck.cpp
@@ -54,13 +54,17 @@
   // 2) inside a range-for over an array
   // 3) if it converts a string literal to a pointer
   Finder->addMatcher(
-      traverse(TK_AsIs,
-               implicitCastExpr(
-                   unless(hasParent(arraySubscriptExpr())),
-                   unless(hasParentIgnoringImpCasts(explicitCastExpr())),
-                   unless(isInsideOfRangeBeginEndStmt()),
-                   unless(hasSourceExpression(ignoringParens(stringLiteral()))))
-                   .bind("cast")),
+      traverse(
+          TK_AsIs,
+          implicitCastExpr(
+              unless(hasParent(arraySubscriptExpr())),
+              unless(hasParentIgnoringImpCasts(explicitCastExpr())),
+              unless(isInsideOfRangeBeginEndStmt()),
+              unless(hasSourceExpression(ignoringParens(stringLiteral()))),
+              unless(hasSourceExpression(ignoringParens(conditionalOperator(
+                  allOf(hasTrueExpression(stringLiteral()),
+                        hasFalseExpression(stringLiteral())))))))
+              .bind("cast")),
       this);
 }
 
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -67,6 +67,10 @@
 Improvements to clang-tidy
 --------------------------
 
+- Make the `cppcoreguidelines-pro-bounds-array-to-pointer-decay` check accept
+  string literal to pointer decay in conditional operator even if operands are
+  of the same length.
+
 - Ignore warnings from macros defined in system headers, if not using the
   `-system-headers` flag.
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-pro-bounds-array-to-pointer-decay.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-pro-bounds-array-to-pointer-decay.cpp
--- a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-pro-bounds-array-to-pointer-decay.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-pro-bounds-array-to-pointer-decay.cpp
@@ -49,3 +49,14 @@
   void *a[2];
   f2(static_cast<void *const*>(a)); // OK, explicit cast
 }
+
+void issue31155(int i) {
+  const char *a = i ? "foo" : "bar";    // OK, decay string literal to pointer
+  const char *b = i ? "foo" : "foobar"; // OK, decay string literal to pointer
+
+  char arr[1];
+  const char *c = i ? arr : "bar";
+  // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: do not implicitly decay an array into a pointer
+  const char *d = i ? "foo" : arr;
+  // CHECK-MESSAGES: :[[@LINE-1]]:31: warning: do not implicitly decay an array into a pointer
+}