diff --git a/sprout/cstring/strcat.hpp b/sprout/cstring/strcat.hpp
index 8a634be0..0d51eaf8 100644
--- a/sprout/cstring/strcat.hpp
+++ b/sprout/cstring/strcat.hpp
@@ -18,7 +18,7 @@ namespace sprout {
 			OutputCStrIterator result = s1;
 			while (*s1++)
 				;
-			while (*s1++ = *s2++)
+			while ((*s1++ = *s2++))
 				;
 			return result;
 		}
diff --git a/sprout/cstring/strcpy.hpp b/sprout/cstring/strcpy.hpp
index f191479f..940b7650 100644
--- a/sprout/cstring/strcpy.hpp
+++ b/sprout/cstring/strcpy.hpp
@@ -16,7 +16,7 @@ namespace sprout {
 		inline SPROUT_CXX14_CONSTEXPR OutputCStrIterator
 		strcpy(OutputCStrIterator s1, CStrIterator s2) {
 			OutputCStrIterator result = s1;
-			while (*s1++ = *s2++)
+			while ((*s1++ = *s2++))
 				;
 			return result;
 		}