diff --git a/rtl/netbsd/pmutext.inc b/rtl/netbsd/pmutext.inc
index b609b4c239..ce7f13ce2a 100644
--- a/rtl/netbsd/pmutext.inc
+++ b/rtl/netbsd/pmutext.inc
@@ -14,5 +14,40 @@
 
 { definition of pthread_mutex_t, because needed in both ptypes.inc and }
 { in sysosh.inc                                                        }
+(* from /usr/include/pthread_types.h 
+struct	__pthread_mutex_st {
+	unsigned int	ptm_magic;
+	pthread_spin_t	ptm_errorcheck;
+#ifdef __CPU_SIMPLE_LOCK_PAD
+	uint8_t		ptm_pad1[3];
+#endif
+	pthread_spin_t	ptm_interlock;	/* unused - backwards compat */
+#ifdef __CPU_SIMPLE_LOCK_PAD
+	uint8_t		ptm_pad2[3];
+#endif
+	volatile pthread_t ptm_owner;
+	pthread_t * volatile ptm_waiters;
+	unsigned int	ptm_recursed;
+	void		*ptm_spare2;	/* unused - backwards compat */
+};
+*)
+
+{$ifdef I386}
+  {$define __CPU_SIMPLE_LOCK_PAD}
+{$endif}
+  record
+    ptm_magic : dword { should be cuint};
+    ptm_errorcheck : char { should be pthread_spin_t};
+{$ifdef __CPU_SIMPLE_LOCK_PAD}
+    ptm_pad : array[0..2] of char;
+{$endif _CPU_SIMPLE_LOCK_PAD}
+    ptm_interlock : char { should be pthread_spinn_t};
+{$ifdef __CPU_SIMPLE_LOCK_PAD}
+    ptm_pad2 : array[0..2] of char;
+{$endif _CPU_SIMPLE_LOCK_PAD}
+    ptm_owner : pointer { should be pthread_t};
+    ptm_waiter :  pointer { should be ppthread_t};
+    ptm_recursed : dword { should be cuint};
+    ptm_spare2 : pointer;
+  end;
 
-pointer;