diff --git a/py/gc.c b/py/gc.c
index 2f60ce50d978241415f1cd926c68bf414c5a8050..d78b70a9cf864dfd18142778eaa832c9cf7c9315 100644
--- a/py/gc.c
+++ b/py/gc.c
@@ -40,7 +40,7 @@
 
 #if MICROPY_ENABLE_GC
 
-#if 0 // print debugging info
+#if 1 // print debugging info
 #define DEBUG_PRINT (1)
 #define DEBUG_printf DEBUG_printf
 #else // don't print debugging info
@@ -113,6 +113,7 @@ STATIC machine_uint_t gc_lock_depth;
 void gc_init(void *start, void *end) {
     // align end pointer on block boundary
     end = (void*)((machine_uint_t)end & (~(BYTES_PER_BLOCK - 1)));
+    DEBUG_printf("Initializing GC heap: %p..%p = " UINT_FMT " bytes\n", start, end, (byte*)end - (byte*)start);
 
     // calculate parameters for GC (T=total, A=alloc table, F=finaliser table, P=pool; all in bytes):
     // T = A + F + P
@@ -120,7 +121,6 @@ void gc_init(void *start, void *end) {
     //     P = A * BLOCKS_PER_ATB * BYTES_PER_BLOCK
     // => T = A * (1 + BLOCKS_PER_ATB / BLOCKS_PER_FTB + BLOCKS_PER_ATB * BYTES_PER_BLOCK)
     machine_uint_t total_byte_len = (byte*)end - (byte*)start;
-    DEBUG_printf("Initializing GC heap: %p..%p = " UINT_FMT " bytes\n", start, end, total_byte_len);
 #if MICROPY_ENABLE_FINALISER
     gc_alloc_table_byte_len = total_byte_len * BITS_PER_BYTE / (BITS_PER_BYTE + BITS_PER_BYTE * BLOCKS_PER_ATB / BLOCKS_PER_FTB + BITS_PER_BYTE * BLOCKS_PER_ATB * BYTES_PER_BLOCK);
 #else
@@ -348,6 +348,7 @@ void gc_info(gc_info_t *info) {
 
 void *gc_alloc(machine_uint_t n_bytes, bool has_finaliser) {
     machine_uint_t n_blocks = ((n_bytes + BYTES_PER_BLOCK - 1) & (~(BYTES_PER_BLOCK - 1))) / BYTES_PER_BLOCK;
+    DEBUG_printf("gc_alloc(" UINT_FMT " bytes -> " UINT_FMT " blocks)\n", n_bytes, n_blocks);
 
     // check if GC is locked
     if (gc_lock_depth > 0) {
@@ -401,7 +402,7 @@ found:
 
     // get pointer to first block
     void *ret_ptr = (void*)(gc_pool_start + start_block * WORDS_PER_BLOCK);
-    DEBUG_printf("gc_alloc(" UINT_FMT " bytes -> " UINT_FMT " blocks ptr %p)\n", n_bytes, n_blocks, ret_ptr);
+    DEBUG_printf("gc_alloc(%p)\n", ret_ptr);
 
     // zero out the additional bytes of the newly allocated blocks
     // This is needed because the blocks may have previously held pointers