diff --git a/include/PICA/shader.hpp b/include/PICA/shader.hpp
index 7f127795..535b6f4c 100644
--- a/include/PICA/shader.hpp
+++ b/include/PICA/shader.hpp
@@ -133,6 +133,10 @@ class PICAShader {
 	Hash lastCodeHash = 0;    // Last hash computed for the shader code (Used for the JIT caching mechanism)
 	Hash lastOpdescHash = 0;  // Last hash computed for the operand descriptors (Also used for the JIT)
 
+  public:
+	bool uniformsDirty = false;
+
+  protected:
 	bool codeHashDirty = false;
 	bool opdescHashDirty = false;
 
@@ -283,6 +287,7 @@ class PICAShader {
 				uniform[2] = f24::fromRaw(((floatUniformBuffer[0] & 0xff) << 16) | (floatUniformBuffer[1] >> 16));
 				uniform[3] = f24::fromRaw(floatUniformBuffer[0] >> 8);
 			}
+			uniformsDirty = true;
 		}
 	}
 
@@ -294,6 +299,12 @@ class PICAShader {
 		u[1] = getBits<8, 8>(word);
 		u[2] = getBits<16, 8>(word);
 		u[3] = getBits<24, 8>(word);
+		uniformsDirty = true;
+	}
+
+	void uploadBoolUniform(u32 value) {
+		boolUniform = value;
+		uniformsDirty = true;
 	}
 
 	void run();
diff --git a/src/core/PICA/regs.cpp b/src/core/PICA/regs.cpp
index c9412fc8..0c5f4adb 100644
--- a/src/core/PICA/regs.cpp
+++ b/src/core/PICA/regs.cpp
@@ -301,7 +301,7 @@ void GPU::writeInternalReg(u32 index, u32 value, u32 mask) {
 		}
 
 		case VertexBoolUniform: {
-			shaderUnit.vs.boolUniform = value & 0xffff;
+			shaderUnit.vs.uploadBoolUniform(value & 0xffff);
 			break;
 		}
 
diff --git a/src/core/PICA/shader_unit.cpp b/src/core/PICA/shader_unit.cpp
index 759849a8..6b291d31 100644
--- a/src/core/PICA/shader_unit.cpp
+++ b/src/core/PICA/shader_unit.cpp
@@ -34,4 +34,5 @@ void PICAShader::reset() {
 
 	codeHashDirty = true;
 	opdescHashDirty = true;
+	uniformsDirty = true;
 }
\ No newline at end of file
diff --git a/src/core/renderer_gl/renderer_gl.cpp b/src/core/renderer_gl/renderer_gl.cpp
index 78dfb98f..6e50f77b 100644
--- a/src/core/renderer_gl/renderer_gl.cpp
+++ b/src/core/renderer_gl/renderer_gl.cpp
@@ -987,7 +987,11 @@ bool RendererGL::prepareForDraw(ShaderUnit& shaderUnit, bool isImmediateMode) {
 		} else {
 			generatedVertexShader = &(*shader);
 			gl.bindUBO(hwShaderUniformUBO);
-			glBufferSubData(GL_UNIFORM_BUFFER, 0, PICAShader::totalUniformSize(), shaderUnit.vs.getUniformPointer());
+
+			if (shaderUnit.vs.uniformsDirty) {
+				shaderUnit.vs.uniformsDirty = false;
+				glBufferSubData(GL_UNIFORM_BUFFER, 0, PICAShader::totalUniformSize(), shaderUnit.vs.getUniformPointer());
+			}
 		}
 	}