diff --git a/gdb/z80-tdep.c b/gdb/z80-tdep.c
index f7e207d0..0c6e1a2a 100644
--- a/gdb/z80-tdep.c
+++ b/gdb/z80-tdep.c
@@ -495,12 +495,15 @@ z80_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
   if (prologue_end != 0)
     {
       struct symtab_and_line prologue_sal = find_sal_for_pc (func_addr, 0);
-      struct compunit_symtab *compunit = prologue_sal.symtab->compunit ();
-      const char *debug_format = compunit->debugformat ();
-
-      if (debug_format != NULL &&
-	 !strncasecmp ("dwarf", debug_format, strlen("dwarf")))
-	return std::max (pc, prologue_end);
+      if (prologue_sal.symtab != nullptr)
+        {
+          struct compunit_symtab *compunit = prologue_sal.symtab->compunit ();
+          const char *debug_format = compunit->debugformat ();
+
+          if (debug_format != nullptr
+              && !strncasecmp ("dwarf", debug_format, strlen ("dwarf")))
+            return std::max (pc, prologue_end);
+        }
     }
 
   return pc;