diff --git a/libtcc.c b/libtcc.c
index b0a9b1a..721b20b 100644
--- a/libtcc.c
+++ b/libtcc.c
@@ -1023,6 +1023,7 @@ LIBTCCAPI TCCState *tcc_new(void)
 #if defined(TCC_TARGET_PE) && 0
     s->leading_underscore = 1;
 #endif
+    s->gcc_packing = 0;
     if (s->section_align == 0)
         s->section_align = ELF_PAGE_SIZE;
 #ifdef TCC_TARGET_I386
@@ -1414,6 +1415,7 @@ static const FlagDef flag_defs[] = {
     { offsetof(TCCState, char_is_unsigned), FD_INVERT, "signed-char" },
     { offsetof(TCCState, nocommon), FD_INVERT, "common" },
     { offsetof(TCCState, leading_underscore), 0, "leading-underscore" },
+    { offsetof(TCCState, gcc_packing), 0, "gcc-packing" },
 };
 
 /* set/reset a flag */
diff --git a/tcc-doc.texi b/tcc-doc.texi
index 4d4a029..a74f84f 100644
--- a/tcc-doc.texi
+++ b/tcc-doc.texi
@@ -239,6 +239,9 @@ Do not generate common symbols for uninitialized data.
 @item -fleading-underscore
 Add a leading underscore at the beginning of each C symbol.
 
address@hidden -fgcc-packing
+Pack bit fields the way GCC does.
+
 @end table
 
 Warning options:
diff --git a/tcc.h b/tcc.h
index 8bca9ae..2ee977f 100644
--- a/tcc.h
+++ b/tcc.h
@@ -567,7 +567,8 @@ struct TCCState {
     /* C language options */
     int char_is_unsigned;
     int leading_underscore;
-    
+    int gcc_packing;
+
     /* warning switches */
     int warn_write_strings;
     int warn_unsupported;
diff --git a/tccgen.c b/tccgen.c
index 7295267..41db5ba 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -2740,6 +2740,7 @@ static void struct_decl(CType *type, int u)
             prevbt = VT_INT;
             bit_pos = 0;
             offset = 0;
+            int bf_req_size = -1;
             while (tok != '}') {
                 parse_btype(&btype, &ad);
                 while (1) {
@@ -2770,7 +2771,7 @@ static void struct_decl(CType *type, int u)
                     if (ad.aligned) {
                         if (align < ad.aligned)
                             align = ad.aligned;
-                    } else if (ad.packed) {
+                    } else if (ad.packed || tcc_state->gcc_packing == 1) {
                         align = 1;
                     } else if (*tcc_state->pack_stack_ptr) {
                         if (align > *tcc_state->pack_stack_ptr)
@@ -2820,11 +2821,32 @@ static void struct_decl(CType *type, int u)
                         /* add new memory data only if starting
                            bit field */
                         if (lbit_pos == 0) {
+                            /* pack bit-fields the same way GCC does */
+                            if (tcc_state->gcc_packing == 1 && bf_req_size > 0) {
+                                if (bf_req_size <= 8)
+                                    bf_req_size = 8;
+                                else if (bf_req_size <= 16)
+                                    bf_req_size = 16;
+                                else if (bf_req_size <= 32)
+                                    bf_req_size = 32;
+                                else
+                                    tcc_error("bitfield larger than 32 bits");
+                                c += bf_req_size / 8;
+                            }
+                            bf_req_size = bit_size;
+
                             if (a == TOK_STRUCT) {
                                 c = (c + align - 1) & -align;
                                 offset = c;
-                                if (size > 0)
-                                    c += size;
+                                if (size > 0) {
+                                    /* pack bit-fields the same way GCC does */
+                                    if (tcc_state->gcc_packing == 1) {
+                                        if (bf_req_size == -1)
+                                            c += size;
+                                    } else {
+                                        c += size;
+                                    }
+                                }
                             } else {
                                 offset = 0;
                                 if (size > c)
@@ -2832,6 +2854,9 @@ static void struct_decl(CType *type, int u)
                             }
                             if (align > maxalign)
                                 maxalign = align;
+                        } else {
+                            /* bit-field continuation */
+                            bf_req_size += bit_size;
                         }
 #if 0
                         printf("add field %s offset=%d", 
@@ -2863,6 +2888,20 @@ static void struct_decl(CType *type, int u)
                 skip(';');
             }
             skip('}');
+
+            /* pack bit-fields the same way GCC does */
+            if (tcc_state->gcc_packing == 1 && bf_req_size > 0) {
+                if (bf_req_size <= 8)
+                    bf_req_size = 8;
+                else if (bf_req_size <= 16)
+                    bf_req_size = 16;
+                else if (bf_req_size <= 32)
+                    bf_req_size = 32;
+                else
+                    tcc_error("bitfield larger than 32 bits");
+                c += bf_req_size / 8;
+            }
+
             /* store size and alignment */
             s->c = (c + maxalign - 1) & -maxalign; 
             s->r = maxalign;