diff --git a/lib/importproject.cpp b/lib/importproject.cpp
index f8cb07f2fc9..4f3364ae88f 100644
--- a/lib/importproject.cpp
+++ b/lib/importproject.cpp
@@ -319,8 +319,12 @@ bool ImportProject::fsParseCommand(FileSettings& fs, const std::string& command)
             (void)Standards::getCPP(fs.standard, unknown_std);
             if (unknown_std) (void)Standards::getC(fs.standard, unknown_std);
             if (unknown_std) {
-                printError("unknown --std value '" + fs.standard + "'");
-                return false;
+                const Standards::cppstd_t gnustd = Standards::getGnuCPP(fs.standard, unknown_std);
+                if (unknown_std) {
+                    printError("unknown --std value '" + fs.standard + "'");
+                    return false;
+                }
+                fs.standard = Standards::getCPP(gnustd);
             }
         } else if (F == 'i' && fval == "system") {
             ++pos;
diff --git a/lib/standards.h b/lib/standards.h
index 51f46633e18..5563e631791 100644
--- a/lib/standards.h
+++ b/lib/standards.h
@@ -149,6 +149,33 @@ struct Standards {
         unknown = true;
         return Standards::CPPLatest;
     }
+    static cppstd_t getGnuCPP(const std::string &std, bool &unknown) {
+        // treat gnu++XX as c++XX
+        unknown = false;
+        if (std == "gnu++03") {
+            return Standards::CPP03;
+        }
+        if (std == "gnu++11") {
+            return Standards::CPP11;
+        }
+        if (std == "gnu++14") {
+            return Standards::CPP14;
+        }
+        if (std == "gnu++17") {
+            return Standards::CPP17;
+        }
+        if (std == "gnu++20") {
+            return Standards::CPP20;
+        }
+        if (std == "gnu++23") {
+            return Standards::CPP23;
+        }
+        if (std == "gnu++26") {
+            return Standards::CPP26;
+        }
+        unknown = true;
+        return Standards::CPPLatest;
+    }
 };
 
 /// @}