diff --git a/audio/audio_filter_param_eq.c b/audio/audio_filter_param_eq.c
index bf3bbcb..688cb36 100644
--- a/audio/audio_filter_param_eq.c
+++ b/audio/audio_filter_param_eq.c
@@ -195,10 +195,10 @@ static BiQuad biquad_initialize(EQBand band, uint32_t sampleRate) {
 #else
 static BiQuad biquad_initialize(EQBand band, uint32_t sampleRate) {
     BiQuad b;
-    double b0, b1, b2, a1, a2;
+    double b0 = 0, b1 = 0, b2 = 0, a1 = 0, a2 = 0;
     double Fc = band.frequency / sampleRate;
     
-    double norm;
+    double norm = 0;
     double V = pow(10, fabs(band.gain) / 20.0);
     double K = tan(M_PI * Fc);