diff --git a/cake/BuildExternals.cake b/cake/BuildExternals.cake
index 6e858a6e..c1dd93d0 100644
--- a/cake/BuildExternals.cake
+++ b/cake/BuildExternals.cake
@@ -429,7 +429,7 @@ Task ("externals-linux")
     .WithCriteria (IsRunningOnLinux ())
     .Does (() => 
 {
-    var SUPPORT_GPU = "1"; // 1 == true, 0 == false
+    var SUPPORT_GPU = EnvironmentVariable ("SUPPORT_GPU") ?? "1"; // 1 == true, 0 == false
 
     var ninja = DEPOT_PATH.CombineWithFilePath ("ninja").FullPath;
 
diff --git a/native-builds/libSkiaSharp_linux/Makefile b/native-builds/libSkiaSharp_linux/Makefile
index cb6af139..fbad6b69 100644
--- a/native-builds/libSkiaSharp_linux/Makefile
+++ b/native-builds/libSkiaSharp_linux/Makefile
@@ -1,6 +1,8 @@
-ARCH = x64
-VERSION = 1.0.0.0
-SUPPORT_GPU = 1
+ARCH ?= x64
+VERSION ?= 1.0.0.0
+SUPPORT_GPU ?= 1
+CC ?= gcc
+CXX ?= g++
 
 noop = 
 space = ${noop} ${noop}
@@ -106,13 +108,17 @@ deps = $(objs:.o=.d)
 ${objarch_root}/%.o: ${src_root}/%
 # build the local source
 	mkdir -p $(dir $@)
-	c++ -MMD -MF $@.d ${defines} ${includes} ${cflags} ${cflags_cc} ${arch_cflags} -c $< -o $@
+	$(CXX) -MMD -MF $@.d                                             \
+	    ${defines} ${includes} ${cflags} ${cflags_cc} ${arch_cflags} \
+		${CFLAGS} ${CXXFLAGS}                                        \
+		-c $< -o $@
 
 ${target}: ${objs}
 # link with skia
 	mkdir -p $(dir $@)
-	c++ -shared -rdynamic -s -o $@                                                \
+	$(CXX) -shared -rdynamic -s -o $@                                             \
 		${defines} ${includes} ${cflags} ${cflags_cc} ${arch_cflags}              \
+		${CFLAGS} ${CXXFLAGS} ${LDXXFLAGS} ${LDFLAGS}                             \
 		-Wl,--start-group ${objarch_root}/*.o  ${library_paths} -Wl,--end-group   \
 		${ldflags} -Wl,--gc-sections -Wl,--no-undefined                           \
 		-Wl,-soname,libSkiaSharp.so.${soname_version}
diff --git a/tests/SkiaSharp.NetCore.Tests/project.json b/tests/SkiaSharp.NetCore.Tests/project.json
index 943654d0..01713630 100644
--- a/tests/SkiaSharp.NetCore.Tests/project.json
+++ b/tests/SkiaSharp.NetCore.Tests/project.json
@@ -29,10 +29,10 @@
     },
     "testRunner": "nunit",
     "frameworks": {
-        "netcoreapp1.0": {
+        "netcoreapp1.1": {
             "dependencies": {
                 "Microsoft.NETCore.App": {
-                    "version": "1.0.0"
+                    "version": "1.1.0"
                 }
             },
             "imports": [
@@ -45,6 +45,9 @@
         "win7-x86": { },
         "osx.10.10-x64": { },
         "osx.10.11-x64": { },
-        "ubuntu.14.04-x64": { }
+        "ubuntu.14.04-x64": { },
+        "ubuntu.14.10-x64": { },
+        "ubuntu.16.04-x64": { },
+        "ubuntu.16.10-x64": { }
     }
 }