diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 5bc10fcef..d48547e0d 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -814,7 +814,7 @@ void Preprocessor::preprocess(std::istream &srcCodeStream, std::string &processe
 
             fin.open(cur.c_str());
             if (!fin.is_open()) {
-                if (_settings && !_settings->nomsg.isSuppressed("missingInclude", cur, 1)) {
+                if (_settings && !_settings->nomsg.isSuppressed("missingInclude", Path::fromNativeSeparators(cur), 1)) {
                     missingIncludeFlag = true;
                     if (_settings->checkConfiguration) {
                         missingInclude(Path::toNativeSeparators(Path::getPathFromFilename(cur)),
@@ -2088,7 +2088,7 @@ std::string Preprocessor::handleIncludes(const std::string &code, const std::str
                     filepath = path;
                 std::ifstream fin;
                 if (!openHeader(filename, includePaths, filepath, fin)) {
-                    if (_settings && !_settings->nomsg.isSuppressed("missingInclude", filename, linenr)) {
+                    if (_settings && !_settings->nomsg.isSuppressed("missingInclude", Path::fromNativeSeparators(filename), linenr)) {
                         missingIncludeFlag = true;
 
                         if (_settings->checkConfiguration)
@@ -2216,7 +2216,7 @@ void Preprocessor::handleIncludes(std::string &code, const std::string &filePath
                 }
             }
 
-            if (!_settings->nomsg.isSuppressed("missingInclude", f, linenr)) {
+            if (!_settings->nomsg.isSuppressed("missingInclude", Path::fromNativeSeparators(f), linenr)) {
                 missingIncludeFlag = true;
                 if (_errorLogger && _settings->checkConfiguration) {
                     missingInclude(Path::toNativeSeparators(f),
diff --git a/lib/suppressions.cpp b/lib/suppressions.cpp
index 307e1ebc8..f318dd0e1 100644
--- a/lib/suppressions.cpp
+++ b/lib/suppressions.cpp
@@ -87,7 +87,7 @@ std::string Suppressions::addSuppressionLine(const std::string &line)
     }
 
     // We could perhaps check if the id is valid and return error if it is not
-    const std::string errmsg(addSuppression(id, file, lineNumber));
+    const std::string errmsg(addSuppression(id, Path::fromNativeSeparators(file), lineNumber));
     if (!errmsg.empty())
         return errmsg;
 
diff --git a/test/testsuppressions.cpp b/test/testsuppressions.cpp
index 7fa46ebc2..e98d5e513 100644
--- a/test/testsuppressions.cpp
+++ b/test/testsuppressions.cpp
@@ -41,6 +41,7 @@ private:
         TEST_CASE(suppressionsFileNameWithExtraPath);
         TEST_CASE(suppressionsSettings);
         TEST_CASE(suppressionsMultiFile);
+        TEST_CASE(suppressionsPathSeparator);
 
         TEST_CASE(inlinesuppress_unusedFunction); // #4210 - unusedFunction
     }
@@ -66,9 +67,9 @@ private:
         Suppressions suppressions;
         std::istringstream s("errorid:c:\\foo.cpp\nerrorid:c:\\bar.cpp:12");
         ASSERT_EQUALS("", suppressions.parseFile(s));
-        ASSERT_EQUALS(true, suppressions.isSuppressed("errorid", "c:\\foo.cpp", 1111));
-        ASSERT_EQUALS(false, suppressions.isSuppressed("errorid", "c:\\bar.cpp", 10));
-        ASSERT_EQUALS(true, suppressions.isSuppressed("errorid", "c:\\bar.cpp", 12));
+        ASSERT_EQUALS(true, suppressions.isSuppressed("errorid", "c:/foo.cpp", 1111));
+        ASSERT_EQUALS(false, suppressions.isSuppressed("errorid", "c:/bar.cpp", 10));
+        ASSERT_EQUALS(true, suppressions.isSuppressed("errorid", "c:/bar.cpp", 12));
     }
 
     void suppressionsGlob() const {
@@ -313,6 +314,12 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void suppressionsPathSeparator() const {
+        Suppressions suppressions;
+        suppressions.addSuppressionLine("*:test\\*");
+        ASSERT_EQUALS(true, suppressions.isSuppressed("someid", "test/foo/bar.cpp", 142));
+    }
+
     void inlinesuppress_unusedFunction() const { // #4210 - wrong report of "unmatchedSuppression" for "unusedFunction"
         Suppressions suppressions;
         suppressions.addSuppression("unusedFunction", "test.c", 3U);