diff --git a/poincare/Makefile b/poincare/Makefile
index aea534ca3..52e07d7dd 100644
--- a/poincare/Makefile
+++ b/poincare/Makefile
@@ -174,6 +174,7 @@ tests_src += $(addprefix poincare/test/,\
   print_float.cpp\
   print_int.cpp\
   rational.cpp\
+  regularized_incomplete_beta_function.cpp \
   simplification.cpp\
 )
 
diff --git a/poincare/test/regularized_incomplete_beta_function.cpp b/poincare/test/regularized_incomplete_beta_function.cpp
new file mode 100644
index 000000000..7f50fd747
--- /dev/null
+++ b/poincare/test/regularized_incomplete_beta_function.cpp
@@ -0,0 +1,19 @@
+#include <quiz.h>
+#include <poincare/regularized_incomplete_beta_function.h>
+#include <float.h>
+#include <cmath>
+
+using namespace Poincare;
+
+void assert_regularized_incomplete_beta_function_is(double a, double b, double x, double result) {
+  double r = RegularizedIncompleteBetaFunction(a, b, x);
+  quiz_assert(std::abs(r - result) < FLT_EPSILON/10.0);
+}
+
+QUIZ_CASE(regularized_incomplete_beta_function) {
+  assert_regularized_incomplete_beta_function_is(1.0, 2.0, 0.0, 0.0);
+  assert_regularized_incomplete_beta_function_is(1.0, 2.0, 1.0, 1.0);
+  assert_regularized_incomplete_beta_function_is(1.7, 0.9, 0.3, 0.114276013523787293056995598423812417112640756984394176432);
+  assert_regularized_incomplete_beta_function_is(7.3, 3.9, 0.4, 0.042393671346062170259328642902287422849467242046012782022);
+  assert_regularized_incomplete_beta_function_is(128.4, 31.5, 0.8, 0.446264065069106243051390524472702916228137487657780205030);
+}