diff --git a/TestScripts/setenv-ios.sh b/TestScripts/setenv-ios.sh
index 10fd1ce5..596ec7e4 100755
--- a/TestScripts/setenv-ios.sh
+++ b/TestScripts/setenv-ios.sh
@@ -195,32 +195,32 @@ fi
 
 # https://github.com/weidai11/cryptopp/issues/635
 if [ "$APPLE_SDK" == "iPhoneSimulator" ]; then
-  IOS_FLAGS += -DCRYPTOPP_DISABLE_SSSE3
+  IOS_FLAGS="$IOS_FLAGS -DCRYPTOPP_DISABLE_SSSE3"
 fi
 
 # Simulator fixup. LD fails to link dylib.
 if [ "$APPLE_SDK" == "iPhoneSimulator" ] && [ "$IOS_ARCH" == "i386" ]; then
-  IOS_FLAGS += -miphoneos-version-min=5
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=5"
 fi
 
 # ARMv7s fixup. Xcode 4/iOS 6
 if [ "$IOS_ARCH" == "armv7s" ]; then
-  IOS_FLAGS += -miphoneos-version-min=6
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=6"
 fi
 
 # ARM64 fixup. Xcode 5/iOS 7
 if [ "$IOS_ARCH" == "arm64" ]; then
-  IOS_FLAGS = -miphoneos-version-min=7
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=7"
 fi
 
 # Yet another ARM64 fixup.
 if [ "$APPLE_SDK" == "AppleTVOS" ]; then
-  IOS_FLAGS = ""
+  IOS_FLAGS=""
 fi
 
 # ARM64 Simulator fixup. Under Xcode 6/iOS 8, it uses x86_64 and not i386
 if [ "$IOS_ARCH" == "x86_64" ]; then
-  IOS_FLAGS += -miphoneos-version-min=8
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=8"
 fi
 
 # Simulator uses i386 or x86_64, Device uses ARMv5, ARMv6, ARMv7, ARMv7s or ARMv8
diff --git a/setenv-ios.sh b/setenv-ios.sh
index 10fd1ce5..596ec7e4 100755
--- a/setenv-ios.sh
+++ b/setenv-ios.sh
@@ -195,32 +195,32 @@ fi
 
 # https://github.com/weidai11/cryptopp/issues/635
 if [ "$APPLE_SDK" == "iPhoneSimulator" ]; then
-  IOS_FLAGS += -DCRYPTOPP_DISABLE_SSSE3
+  IOS_FLAGS="$IOS_FLAGS -DCRYPTOPP_DISABLE_SSSE3"
 fi
 
 # Simulator fixup. LD fails to link dylib.
 if [ "$APPLE_SDK" == "iPhoneSimulator" ] && [ "$IOS_ARCH" == "i386" ]; then
-  IOS_FLAGS += -miphoneos-version-min=5
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=5"
 fi
 
 # ARMv7s fixup. Xcode 4/iOS 6
 if [ "$IOS_ARCH" == "armv7s" ]; then
-  IOS_FLAGS += -miphoneos-version-min=6
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=6"
 fi
 
 # ARM64 fixup. Xcode 5/iOS 7
 if [ "$IOS_ARCH" == "arm64" ]; then
-  IOS_FLAGS = -miphoneos-version-min=7
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=7"
 fi
 
 # Yet another ARM64 fixup.
 if [ "$APPLE_SDK" == "AppleTVOS" ]; then
-  IOS_FLAGS = ""
+  IOS_FLAGS=""
 fi
 
 # ARM64 Simulator fixup. Under Xcode 6/iOS 8, it uses x86_64 and not i386
 if [ "$IOS_ARCH" == "x86_64" ]; then
-  IOS_FLAGS += -miphoneos-version-min=8
+  IOS_FLAGS="$IOS_FLAGS -miphoneos-version-min=8"
 fi
 
 # Simulator uses i386 or x86_64, Device uses ARMv5, ARMv6, ARMv7, ARMv7s or ARMv8