diff --git a/hls4ml/templates/catapult/build_lib.sh b/hls4ml/templates/catapult/build_lib.sh
index 2c7a11c626..6fedb3089a 100755
--- a/hls4ml/templates/catapult/build_lib.sh
+++ b/hls4ml/templates/catapult/build_lib.sh
@@ -1,13 +1,13 @@
 #!/bin/bash
 
 CC=g++
-if [[ "$OSTYPE" == "linux-gnu" ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11 -fno-gnu-unique"
-elif [[ "$OSTYPE" == "linux"* ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11 -fno-gnu-unique -Wno-pragmas"
-elif [[ "$OSTYPE" == "darwin"* ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11"
+CFLAGS="-O3 -fPIC -std=c++11"
+
+# Include -fno-gnu-unique if it is there
+if echo "" | ${CC} -Werror -fsyntax-only -fno-gnu-unique -xc++ - -o /dev/null &> /dev/null; then
+  CFLAGS+=" -fno-gnu-unique -Wno-pragmas"
 fi
+
 LDFLAGS=
 
 # Pick up AC libraries from Catapult install first
diff --git a/hls4ml/templates/quartus/build_lib.sh b/hls4ml/templates/quartus/build_lib.sh
index 5514a9cc75..2a0d4498b1 100755
--- a/hls4ml/templates/quartus/build_lib.sh
+++ b/hls4ml/templates/quartus/build_lib.sh
@@ -2,11 +2,13 @@
 set -e
 
 CC=g++
-if [[ "$OSTYPE" == "linux-gnu" ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11 -fno-gnu-unique"
-elif [[ "$OSTYPE" == "darwin"* ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11"
+CFLAGS="-O3 -fPIC -std=c++11"
+
+# Include -fno-gnu-unique if it is there
+if echo "" | ${CC} -Werror -fsyntax-only -fno-gnu-unique -xc++ - -o /dev/null &> /dev/null; then
+  CFLAGS+=" -fno-gnu-unique"
 fi
+
 LDFLAGS=
 INCFLAGS="-Ifirmware/ac_types/ -Ifirmware/ap_types/"
 PROJECT=myproject
diff --git a/hls4ml/templates/symbolic/build_lib.sh b/hls4ml/templates/symbolic/build_lib.sh
index 3c07926e26..9db3b1a6ff 100755
--- a/hls4ml/templates/symbolic/build_lib.sh
+++ b/hls4ml/templates/symbolic/build_lib.sh
@@ -1,11 +1,13 @@
 #!/bin/bash
 
 CC=g++
-if [[ "$OSTYPE" == "linux-gnu" ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11 -fno-gnu-unique"
-elif [[ "$OSTYPE" == "darwin"* ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11"
+CFLAGS="-O3 -fPIC -std=c++11"
+
+# Include -fno-gnu-unique if it is there
+if echo "" | ${CC} -Werror -fsyntax-only -fno-gnu-unique -xc++ - -o /dev/null &> /dev/null; then
+  CFLAGS+=" -fno-gnu-unique"
 fi
+
 HLS_LIBS_PATH=mylibspath
 LDFLAGS="-Wl,--no-undefined -Wl,--no-allow-shlib-undefined -Wl,--no-as-needed -Wl,-rpath,${HLS_LIBS_PATH}/lib/csim -L ${HLS_LIBS_PATH}/lib/csim -lhlsmc++-GCC46 -lhlsm-GCC46 -fno-builtin -fno-inline -Wl,-rpath,${HLS_LIBS_PATH}/tools/fpo_v7_0 -L ${HLS_LIBS_PATH}/tools/fpo_v7_0 -lgmp -lmpfr -lIp_floating_point_v7_0_bitacc_cmodel"
 INCFLAGS="-Ifirmware/ap_types/"
diff --git a/hls4ml/templates/vivado/build_lib.sh b/hls4ml/templates/vivado/build_lib.sh
index df719e2305..dc4ffbd43d 100755
--- a/hls4ml/templates/vivado/build_lib.sh
+++ b/hls4ml/templates/vivado/build_lib.sh
@@ -2,11 +2,13 @@
 set -e
 
 CC=g++
-if [[ "$OSTYPE" == "linux-gnu" ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11 -fno-gnu-unique"
-elif [[ "$OSTYPE" == "darwin"* ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11"
+CFLAGS="-O3 -fPIC -std=c++11"
+
+# Include -fno-gnu-unique if it is there
+if echo "" | ${CC} -Werror -fsyntax-only -fno-gnu-unique -xc++ - -o /dev/null &> /dev/null; then
+  CFLAGS+=" -fno-gnu-unique"
 fi
+
 LDFLAGS=
 INCFLAGS="-Ifirmware/ap_types/"
 PROJECT=myproject
diff --git a/hls4ml/templates/vivado_accelerator/build_lib.sh b/hls4ml/templates/vivado_accelerator/build_lib.sh
index fa0ec26ded..bef29b0eb5 100755
--- a/hls4ml/templates/vivado_accelerator/build_lib.sh
+++ b/hls4ml/templates/vivado_accelerator/build_lib.sh
@@ -1,11 +1,13 @@
 #!/bin/bash
 
 CC=g++
-if [[ "$OSTYPE" == "linux-gnu" ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11 -fno-gnu-unique"
-elif [[ "$OSTYPE" == "darwin"* ]]; then
-    CFLAGS="-O3 -fPIC -std=c++11"
+CFLAGS="-O3 -fPIC -std=c++11"
+
+# Include -fno-gnu-unique if it is there
+if echo "" | ${CC} -Werror -fsyntax-only -fno-gnu-unique -xc++ - -o /dev/null &> /dev/null; then
+  CFLAGS+=" -fno-gnu-unique"
 fi
+
 INCFLAGS="-Ifirmware/ap_types/"
 PROJECT=myproject
 LIB_STAMP=mystamp