diff --git a/configure.ac b/configure.ac
index 81a247a696c..8b26d0882f3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2224,7 +2224,7 @@ AC_CACHE_CHECK([for flags to work around GCC bug 58416],
 	       [AC_LANG_DEFINES_PROVIDED
 		[/* Work around GCC bug with double in unions on x86,
 		    where the generated insns copy non-floating-point data
-		    via fldl/fstpl instruction pairs.  This can misbehave
+		    via fldl/fstpl instruction pairs.  This can misbehave if
 		    the data's bit pattern looks like a NaN.  See, e.g.:
 		       https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58416#c10
 		       https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71460