diff --git a/src/api/api_rcf.cpp b/src/api/api_rcf.cpp
index 684e8c617..3bef38f0e 100644
--- a/src/api/api_rcf.cpp
+++ b/src/api/api_rcf.cpp
@@ -385,7 +385,7 @@ extern "C" {
         Z3_CATCH_RETURN(nullptr);
     }
 
-    int Z3_API Z3_rcf_interval(Z3_context c, Z3_rcf_num a, int * lower_is_inf, int * lower_is_open, Z3_rcf_num * lower, int * upper_is_inf, int * upper_is_open, Z3_rcf_num * upper) {
+    int Z3_API Z3_rcf_interval(Z3_context c, Z3_rcf_num a, bool * lower_is_inf, bool * lower_is_open, Z3_rcf_num * lower, bool * upper_is_inf, bool * upper_is_open, Z3_rcf_num * upper) {
         Z3_TRY;
         LOG_Z3_rcf_interval(c, a, lower_is_inf, lower_is_open, lower, upper_is_inf, upper_is_open, upper);
         RESET_ERROR_CODE();
diff --git a/src/api/z3_rcf.h b/src/api/z3_rcf.h
index b3842f1b6..4286f1c43 100644
--- a/src/api/z3_rcf.h
+++ b/src/api/z3_rcf.h
@@ -272,9 +272,9 @@ extern "C" {
 
        \pre Z3_rcf_is_algebraic(ctx, a);
 
-       def_API('Z3_rcf_interval', INT, (_in(CONTEXT), _in(RCF_NUM), _out(INT), _out(INT), _out(RCF_NUM), _out(INT), _out(INT), _out(RCF_NUM)))
+       def_API('Z3_rcf_interval', INT, (_in(CONTEXT), _in(RCF_NUM), _out(BOOL), _out(BOOL), _out(RCF_NUM), _out(BOOL), _out(BOOL), _out(RCF_NUM)))
    */
-   int Z3_API Z3_rcf_interval(Z3_context c, Z3_rcf_num a, int * lower_is_inf, int * lower_is_open, Z3_rcf_num * lower, int * upper_is_inf, int * upper_is_open, Z3_rcf_num * upper);
+   int Z3_API Z3_rcf_interval(Z3_context c, Z3_rcf_num a, bool * lower_is_inf, bool * lower_is_open, Z3_rcf_num * lower, bool * upper_is_inf, bool * upper_is_open, Z3_rcf_num * upper);
 
    /**
        \brief Return the number of sign conditions of an algebraic number.
diff --git a/src/math/realclosure/realclosure.cpp b/src/math/realclosure/realclosure.cpp
index 63e942989..0e6cc36f0 100644
--- a/src/math/realclosure/realclosure.cpp
+++ b/src/math/realclosure/realclosure.cpp
@@ -3429,7 +3429,7 @@ namespace realclosure {
             }
         }
 
-        bool get_interval(numeral const & a, int & lower_is_inf, int & lower_is_open, numeral & lower, int & upper_is_inf, int & upper_is_open, numeral & upper)
+        bool get_interval(numeral const & a, bool & lower_is_inf, bool & lower_is_open, numeral & lower, bool & upper_is_inf, bool & upper_is_open, numeral & upper)
         {
             if (!is_algebraic(a))
                 return false;
@@ -6475,7 +6475,7 @@ namespace realclosure {
         return m_imp->get_sign_condition_sign(a, i);
     }
 
-    bool manager::get_interval(numeral const & a, int & lower_is_inf, int & lower_is_open, numeral & lower, int & upper_is_inf, int & upper_is_open, numeral & upper)
+    bool manager::get_interval(numeral const & a, bool & lower_is_inf, bool & lower_is_open, numeral & lower, bool & upper_is_inf, bool & upper_is_open, numeral & upper)
     {
         return m_imp->get_interval(a, lower_is_inf, lower_is_open, lower, upper_is_inf, upper_is_open, upper);
     }
diff --git a/src/math/realclosure/realclosure.h b/src/math/realclosure/realclosure.h
index 12247627b..a1fae3e2b 100644
--- a/src/math/realclosure/realclosure.h
+++ b/src/math/realclosure/realclosure.h
@@ -298,7 +298,7 @@ namespace realclosure {
 
         int get_sign_condition_sign(numeral const &a, unsigned i);
 
-        bool get_interval(numeral const & a, int & lower_is_inf, int & lower_is_open, numeral & lower, int & upper_is_inf, int & upper_is_open, numeral & upper);
+        bool get_interval(numeral const & a, bool & lower_is_inf, bool & lower_is_open, numeral & lower, bool & upper_is_inf, bool & upper_is_open, numeral & upper);
 
         unsigned num_sign_condition_coefficients(numeral const &a, unsigned i);