diff --git a/src/ImageFilter.cpp b/src/ImageFilter.cpp
index c4095f8..2dae8a2 100644
--- a/src/ImageFilter.cpp
+++ b/src/ImageFilter.cpp
@@ -1,4 +1,4 @@
-/*
+/*
  * This file is part of vimix - video live mixer
  *
  * **Copyright** (C) 2019-2023 Bruno Herbelin <bruno.herbelin@gmail.com>
@@ -435,7 +435,8 @@ FilteringProgram ImageFilter::program () const
 }
 
 #define REGEX_UNIFORM_DECLARATION "uniform\\s+float\\s+"
-#define REGEX_UNIFORM_VALUE "(\\s*=\\s*[[:digit:]](\\.[[:digit:]])?)?\\s*\\;"
+#define REGEX_VARIABLE_NAME "[a-zA-Z_][\\w]+"
+#define REGEX_UNIFORM_VALUE "(\\s*=\\s*[[:digit:]]+(\\.[[:digit:]]*)?)?\\s*\\;"
 
 void ImageFilter::setProgram(const FilteringProgram &f, std::promise<std::string> *ret)
 {
@@ -453,7 +454,7 @@ void ImageFilter::setProgram(const FilteringProgram &f, std::promise<std::string
     // Search for "uniform float", a variable name, with possibly a '=' and float value
     std::string glslcode(codes.first);
     std::smatch found_uniform;
-    std::regex is_a_uniform(REGEX_UNIFORM_DECLARATION "[[:alpha:]]+" REGEX_UNIFORM_VALUE);
+    std::regex is_a_uniform(REGEX_UNIFORM_DECLARATION REGEX_VARIABLE_NAME REGEX_UNIFORM_VALUE);
     // loop over every uniform declarations in the GLSL code
     while (std::regex_search(glslcode, found_uniform, is_a_uniform)) {
         // found a complete declaration of uniform variable
@@ -468,9 +469,12 @@ void ImageFilter::setProgram(const FilteringProgram &f, std::promise<std::string
 
         // try to find a value in uniform declaration, and set parameter value if valid
         float val = 0.f;
+        std::string valuestring =
+            std::regex_replace(declaration,std::regex(REGEX_UNIFORM_DECLARATION),"");
+        valuestring = std::regex_replace(valuestring, std::regex(REGEX_VARIABLE_NAME),"");
         std::smatch found_value;
-        std::regex is_a_float_value("[[:digit:]](\\.[[:digit:]])?");
-        if (std::regex_search(declaration, found_value, is_a_float_value)) {
+        std::regex is_a_float_value("[[:digit:]]+(\\.[[:digit:]]*)?");
+        if (std::regex_search(valuestring, found_value, is_a_float_value)) {
             // set value only if a value is given
             if ( BaseToolkit::is_a_value(found_value.str(), &val) )
                 program_.setParameter(varname, val);
diff --git a/src/ImageFilter.h b/src/ImageFilter.h
index afc5e8c..6926a1e 100644
--- a/src/ImageFilter.h
+++ b/src/ImageFilter.h
@@ -56,6 +56,7 @@ public:
     inline std::map< std::string, float > parameters() const { return parameters_; }
 
     // set the value of a parameter
+    inline void clearParameters() { parameters_.clear(); }
     inline void setParameter(const std::string &p, float value) { parameters_[p] = value; }
     bool hasParameter(const std::string &p);
     void removeParameter(const std::string &p);
diff --git a/src/ShaderEditWindow.cpp b/src/ShaderEditWindow.cpp
index 60fc024..20b508a 100644
--- a/src/ShaderEditWindow.cpp
+++ b/src/ShaderEditWindow.cpp
@@ -109,6 +109,7 @@ void ShaderEditWindow::BuildShader()
 
         // set the code of the current filter
         filters_[current_].setCode( { _editor.GetText(), "" } );
+        filters_[current_].clearParameters();
 
         // filter changed, cannot be named as before
         filters_[current_].setName("Custom");