diff --git a/lib_com/options.h b/lib_com/options.h
index f922513d564692e4b01ee1e012252d320d4051b1..a3d14ba61db1ed98980838ce418ac32ae89eee1f 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -96,6 +96,7 @@
 #define FIX_2178_FL_TO_FX_WITH_OBJ_EDIT_FILE_INTERFACE       /* Nokia: Fixes float  to fx conversion in decoder app with object edit file interface */
 #define FIX_2070_JBM_TC_CHANNEL_RESCALING_ISSUE              /* Eri/Orange: scale_sig32 problem on p_tc_fx[] */
 
+#define FIX_2173_UBSAN_IN_JBM_PCMDSP_APA                     /* FhG: Fix UBSAN problems in jbm_pcmdsp_apa_fx.c */
 #define FIX_1947_DEC_HIGH_MLD_FOR_STEREO2MONO                /* FhG: Make Q-factor of synth_16_fx and output_16_fx dynamic to prevent overflow in HQ_CORE mode */
 /* ################### End FIXES switches ########################### */
 
diff --git a/lib_dec/jbm_pcmdsp_apa_fx.c b/lib_dec/jbm_pcmdsp_apa_fx.c
index 37e3f51a755bfa0c4faf5aaded471bfd3c6824b5..bc9ef573f8339baec7b10a82e745e8852cc3d8a8 100644
--- a/lib_dec/jbm_pcmdsp_apa_fx.c
+++ b/lib_dec/jbm_pcmdsp_apa_fx.c
@@ -127,7 +127,11 @@ struct apa_state_t
     UWord16 qualityred;      /* quality reduction threshold */
     UWord16 qualityrise;     /* quality rising for adaptive quality thresholds */
 
-    UWord16 last_pitch;       /* last pitch/sync position */
+#ifdef FIX_2173_UBSAN_IN_JBM_PCMDSP_APA
+    Word16 last_pitch; /* last pitch/sync position */
+#else
+    UWord16 last_pitch;     /* last pitch/sync position */
+#endif
     UWord16 bad_frame_count;  /* # frames before quality threshold is lowered */
     UWord16 good_frame_count; /* # scaled frames */
 
@@ -1392,7 +1396,11 @@ static Word8 logarithmic_search_fx( const apa_state_t *ps,
 
     DO
     {
+#ifdef FIX_2173_UBSAN_IN_JBM_PCMDSP_APA
+        coeff_max = INT32_MIN; /* will always be overwritten with result of first correlation */
+#else
         coeff_max = 0x80000000; /* will always be overwritten with result of first correlation */
+#endif
         move32();
 
         FOR( i = s_start; i < s_start + inlen; i += css * ps->num_channels )