diff --git a/src/ipa/libipa/histogram.cpp b/src/ipa/libipa/histogram.cpp
index 10e44b54a0cf..ea042f0a17b9 100644
--- a/src/ipa/libipa/histogram.cpp
+++ b/src/ipa/libipa/histogram.cpp
@@ -130,7 +130,8 @@ double Histogram::quantile(double q, uint32_t first, uint32_t last) const
 	if (cumulative_[first + 1] == cumulative_[first])
 		frac = 0;
 	else
-		frac = (item - cumulative_[first]) / (cumulative_[first + 1] - cumulative_[first]);
+		frac = (q * total() - cumulative_[first])
+		     / (cumulative_[first + 1] - cumulative_[first]);
 	return first + frac;
 }
 
diff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build
index 83c84bd8c227..8c63ebd8e2f7 100644
--- a/test/ipa/libipa/meson.build
+++ b/test/ipa/libipa/meson.build
@@ -2,7 +2,7 @@
 
 libipa_test = [
     {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']},
-    {'name': 'histogram', 'sources': ['histogram.cpp'], 'should_fail': true},
+    {'name': 'histogram', 'sources': ['histogram.cpp']},
     {'name': 'interpolator', 'sources': ['interpolator.cpp']},
 ]