diff --git a/gui/ConfigHelper.cpp b/gui/ConfigHelper.cpp
index 4491200..401539b 100644
--- a/gui/ConfigHelper.cpp
+++ b/gui/ConfigHelper.cpp
@@ -3,7 +3,7 @@
 #include <optional>
 #include <unistd.h>
 
-char *OpenFile() {
+static char *OpenFile() {
     char *filename = new char[512];
     char cwd[1024];
     char command[2048] = R"(zenity --file-selection --title="Select a config file" 2> /dev/null)";
@@ -25,7 +25,7 @@ char *OpenFile() {
     return res;
 }
 
-char *SaveFile() {
+static char *SaveFile() {
     char *filename = new char[512];
     char cwd[1024];
     char command[2048] = R"(zenity --save --file-selection --title="Save Config" 2> /dev/null)";
diff --git a/gui/CustomCurve.cpp b/gui/CustomCurve.cpp
index 66949f6..70a8f30 100644
--- a/gui/CustomCurve.cpp
+++ b/gui/CustomCurve.cpp
@@ -27,7 +27,7 @@ void CustomCurve::ApplyCurveConstraints() {
 }
 
 // Cubic Bezier derivatives
-ImVec2 BezierFirstOrderDerivative(ImVec2 p0, ImVec2 p1, ImVec2 p2, ImVec2 p3, float t) {
+static ImVec2 BezierFirstOrderDerivative(ImVec2 p0, ImVec2 p1, ImVec2 p2, ImVec2 p3, float t) {
     float u = (1 - t);
     float w1 = 3 * (u * u);
     float w2 = 6 * (u * t);
@@ -35,7 +35,7 @@ ImVec2 BezierFirstOrderDerivative(ImVec2 p0, ImVec2 p1, ImVec2 p2, ImVec2 p3, fl
     return ((p1 - p0) * w1) + ((p2 - p1) * w2) + ((p3 - p2) * w3);
 }
 
-ImVec2 BezierSecondOrderDerivative(ImVec2 p0, ImVec2 p1, ImVec2 p2, ImVec2 p3, float t) {
+static ImVec2 BezierSecondOrderDerivative(ImVec2 p0, ImVec2 p1, ImVec2 p2, ImVec2 p3, float t) {
     float u = (1 - t);
     float w1 = 6 * u;
     float w2 = 6 * t;
diff --git a/gui/DriverHelper.cpp b/gui/DriverHelper.cpp
index 79a0186..c4f9c9e 100644
--- a/gui/DriverHelper.cpp
+++ b/gui/DriverHelper.cpp
@@ -14,7 +14,7 @@
 #include <ImGui/implot.h>
 
 template<typename Ty>
-bool GetParameterTy(const std::string &param_name, Ty &value) {
+static bool GetParameterTy(const std::string &param_name, Ty &value) {
     try {
         using namespace std;
         ifstream file(YEETMOUSE_PARAMS_DIR + param_name);
@@ -31,7 +31,7 @@ bool GetParameterTy(const std::string &param_name, Ty &value) {
     }
 }
 
-bool GetParameterTy(const std::string &param_name, std::string &value) {
+static bool GetParameterTy(const std::string &param_name, std::string &value) {
     try {
         using namespace std;
         ifstream file(YEETMOUSE_PARAMS_DIR + param_name);
@@ -152,7 +152,7 @@ namespace DriverHelper {
     }
 
     bool SaveParameters() {
-        return SetParameterTy("update", (int) 1);
+        return SetParameterTy("update", 1);
     }
 
     bool SavePersistentParameters() {
diff --git a/gui/FunctionHelper.h b/gui/FunctionHelper.h
index 3711923..7f3df81 100644
--- a/gui/FunctionHelper.h
+++ b/gui/FunctionHelper.h
@@ -22,7 +22,7 @@ class CachedFunction {
     CachedFunction(float xStride, Parameters *params);
 
     CachedFunction() {
-    };
+    }
 
     float EvalFuncAt(float x) const;
 
@@ -53,7 +53,7 @@ class CachedFunction {
         static constexpr bool velocity = true;
 
         std::vector<double> data;
-        double xStart;
+        double xStart = 1.0;
     } synchronous_data;
 
     bool SynchronousBuildLUT();
diff --git a/gui/Makefile b/gui/Makefile
index 6080be7..277d3d9 100644
--- a/gui/Makefile
+++ b/gui/Makefile
@@ -4,12 +4,18 @@ CXXFLAGS = -std=c++17 -I . -isystem External
 
 # ImPlot has few of these
 IMGUIFLAGS = -Wformat=0 -Wno-format-security
+WARNFLAGS = -Wall -Wextra -pedantic -Wnon-virtual-dtor -Woverloaded-virtual -Wmisleading-indentation -Wformat=2 -Wextra-semi -Wzero-as-null-pointer-constant -Winit-self -Wmissing-declarations -Wdeprecated -Wcast-qual -Wcast-align -Wctor-dtor-privacy -Wno-sign-compare -Wno-unused-parameter
+
+ifeq (g++, $(CXX))
+    WARNFLAGS += -Wduplicated-cond -Wduplicated-branches -Wuseless-cast -Wlogical-op
+endif
+
 ifneq (,$(findstring clang,$(CXX)))
     # ImGui produces many of these
     IMGUIFLAGS += -Wno-nontrivial-memcall
+    WARNFLAGS += -Wstring-conversion -Wsuggest-override -Wno-overlength-strings
 endif
 
-WARNFLAGS = -Wall -Wno-sign-compare
 OPTIMIZATION_FLAGS = -O2 -flto=auto
 DEBUG_FLAGS = -g -O0
 
diff --git a/gui/gui.cpp b/gui/gui.cpp
index 5987251..e5e45fb 100755
--- a/gui/gui.cpp
+++ b/gui/gui.cpp
@@ -17,7 +17,7 @@ static void glfw_error_callback(int error, const char* description)
 
 // Use the default initialization that comes with ImGui as an Example
 
-void SetupImGuiStyle()
+static void SetupImGuiStyle()
 {
     // nice dark style from ImThemes
     ImGuiStyle& style = ImGui::GetStyle();
diff --git a/gui/main.cpp b/gui/main.cpp
index 1a93643..669fbfa 100644
--- a/gui/main.cpp
+++ b/gui/main.cpp
@@ -47,7 +47,7 @@ void ResetParameters();
                             if(selected_device >= devices.size())    \
                             selected_device = devices.size() - 1;}
 
-int OnGui() {
+static int OnGui() {
     using namespace std::chrono;
 
     ImGuiContext &g = *GImGui;