diff --git a/graalpython/com.oracle.graal.python.pegparser/src/com/oracle/graal/python/pegparser/tokenizer/SourceRange.java b/graalpython/com.oracle.graal.python.pegparser/src/com/oracle/graal/python/pegparser/tokenizer/SourceRange.java
index 5bc0e0d9c1..14c494e99b 100644
--- a/graalpython/com.oracle.graal.python.pegparser/src/com/oracle/graal/python/pegparser/tokenizer/SourceRange.java
+++ b/graalpython/com.oracle.graal.python.pegparser/src/com/oracle/graal/python/pegparser/tokenizer/SourceRange.java
@@ -66,7 +66,7 @@ public SourceRange withEnd(int newEndLine, int newEndColumn) {
 
     public SourceRange startLineShiftColumn(int shift) {
         assert shift >= 0;
-        if (shift == 0) {
+        if (shift == 0 || this == ARTIFICIAL_RANGE) {
             return this;
         }
         return new SourceRange(startLine, startColumn, startLine, startColumn + shift);
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/bytecode_dsl/RootNodeCompiler.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/bytecode_dsl/RootNodeCompiler.java
index 5ec45f3742..f0ae8d5439 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/bytecode_dsl/RootNodeCompiler.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/bytecode_dsl/RootNodeCompiler.java
@@ -816,7 +816,7 @@ void beginRootSourceSection(SSTNode node, Builder b) {
     }
 
     private static void beginSourceSectionInner(Builder b, SourceRange sourceRange) {
-        if (sourceRange.startLine >= 1) {
+        if (sourceRange.startLine >= 1 && sourceRange != SourceRange.ARTIFICIAL_RANGE) {
             if (sourceRange.startColumn >= 0 && sourceRange.endLine >= sourceRange.startLine && sourceRange.endColumn >= 0) {
                 if (sourceRange.endColumn > 0) {
                     b.beginSourceSection(sourceRange.startLine, sourceRange.startColumn + 1, sourceRange.endLine, sourceRange.endColumn);
@@ -4120,6 +4120,7 @@ public Void visit(StmtTy.FunctionDef node) {
         }
 
         public void emitFunctionDef(StmtTy node, String name, ArgumentsTy args, StmtTy[] body, ExprTy[] decoratorList, ExprTy returns, TypeParamTy[] typeParams) {
+            // For instrumentation, we want to map this statement only to the declaration line, such
             // that, e.g., breakpoints inside the body fire only once the body actually executes and
             // not is declared. There is no simple way to get the exact line width here, so we just
             // approximate it with name width.