diff --git a/libyul/AsmJsonConverter.h b/libyul/AsmJsonConverter.h
index 360fa6a36..b350689fc 100644
--- a/libyul/AsmJsonConverter.h
+++ b/libyul/AsmJsonConverter.h
@@ -20,6 +20,8 @@
  * Converts inline assembly AST to JSON format
  */
 
+#pragma once
+
 #include <libyul/AsmDataForward.h>
 #include <liblangutil/SourceLocation.h>
 #include <json/json.h>
diff --git a/tools/solidityUpgrade/SourceTransform.h b/tools/solidityUpgrade/SourceTransform.h
index 2b42471c1..a33a1d97e 100644
--- a/tools/solidityUpgrade/SourceTransform.h
+++ b/tools/solidityUpgrade/SourceTransform.h
@@ -15,6 +15,8 @@
 	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#pragma once
+
 #include <libsolidity/analysis/OverrideChecker.h>
 
 #include <libsolidity/ast/AST.h>