diff --git a/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp b/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp
index 89cfcae15f..1b1a24753c 100644
--- a/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp
+++ b/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp
@@ -344,7 +344,7 @@ private:
   const ControlState m_value{};
 };
 
-ParseResult MakeLiteralExpression(Token token)
+static ParseResult MakeLiteralExpression(Token token)
 {
   ControlState val{};
   if (TryParse(token.data, &val))
diff --git a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
index 029ea22d3c..c825da6b7b 100644
--- a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
@@ -204,7 +204,7 @@ static int s_wakeup_eventfd;
 // sysfs is not stable, so this is probably the easiest way to get a name for a node.
 static std::map<std::string, std::weak_ptr<evdevDevice>> s_devnode_objects;
 
-std::shared_ptr<evdevDevice> FindDeviceWithUniqueID(const char* unique_id)
+static std::shared_ptr<evdevDevice> FindDeviceWithUniqueID(const char* unique_id)
 {
   if (!unique_id)
     return nullptr;
@@ -223,7 +223,7 @@ std::shared_ptr<evdevDevice> FindDeviceWithUniqueID(const char* unique_id)
   return nullptr;
 }
 
-void AddDeviceNode(const char* devnode)
+static void AddDeviceNode(const char* devnode)
 {
   // Unfortunately udev gives us no way to filter out the non event device interfaces.
   // So we open it and see if it works with evdev ioctls or not.
diff --git a/Source/Core/VideoBackends/Vulkan/ShaderCompiler.cpp b/Source/Core/VideoBackends/Vulkan/ShaderCompiler.cpp
index 7b6beb11b0..fb267b9319 100644
--- a/Source/Core/VideoBackends/Vulkan/ShaderCompiler.cpp
+++ b/Source/Core/VideoBackends/Vulkan/ShaderCompiler.cpp
@@ -107,8 +107,10 @@ static const char SUBGROUP_HELPER_HEADER[] = R"(
   #define SUBGROUP_MAX(value) value = subgroupMax(value)
 )";
 
-std::optional<SPIRVCodeVector> CompileShaderToSPV(EShLanguage stage, const char* stage_filename,
-                                                  std::string_view source, std::string_view header)
+static std::optional<SPIRVCodeVector> CompileShaderToSPV(EShLanguage stage,
+                                                         const char* stage_filename,
+                                                         std::string_view source,
+                                                         std::string_view header)
 {
   if (!InitializeGlslang())
     return std::nullopt;