diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index afabb04aa..674ff12be 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-27  Markus Eisenmann  <meisenmann.lba@fh-salzburg.ac.at>
+
+	* libc/machine/arm/strlen-armv7.S: Fix prepocessor check to avoid
+	double definition of strlen.
+
 2015-08-27  Andre Vieira  <andre.simoesdiasvieira@arm.com>
 
 	* libc/include/sys/_intsup.h: Defined new __INTxx, __FASTxx and
diff --git a/newlib/libc/machine/arm/strlen-armv7.S b/newlib/libc/machine/arm/strlen-armv7.S
index 1aa51c9fb..cb6ba080d 100644
--- a/newlib/libc/machine/arm/strlen-armv7.S
+++ b/newlib/libc/machine/arm/strlen-armv7.S
@@ -37,7 +37,7 @@
 /* NOTE: This ifdef MUST match the ones in arm/strlen.c
    We fallback to the one in arm/strlen.c for size optimised or
    for older architectures. */
-#if defined(_ISA_ARM_7) || defined(__ARM_ARCH_6T2__) && \
+#if (defined(_ISA_ARM_7) || defined(__ARM_ARCH_6T2__)) && \
     !(defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
       (defined (__thumb__) && !defined (__thumb2__)))