diff --git a/src/orbits.cpp b/src/orbits.cpp
index b4da039..c3703b5 100644
--- a/src/orbits.cpp
+++ b/src/orbits.cpp
@@ -68,9 +68,9 @@ orbitInit(double a, double e, double iota, double ohm, double omega, double nu)
 glm::dvec3
 orbitGetEccentricityVector(glm::dvec3 r, glm::dvec3 v, double mu)
 {
-	double v_mag = glm::dot(v, v);
-	double r_mag = glm::dot(r, r);
-	return 1 / mu * ((v_mag - mu / r_mag) * r - (glm::dot(r, v) * v));
+	double v_mag = orbitGetVectorMagnitude(v);
+	double r_mag = orbitGetVectorMagnitude(r);
+	return 1 / mu * ((pow(v_mag, 2) - mu / r_mag) * r - (glm::dot(r, v) * v));
 }
 
 glm::dvec3
@@ -102,6 +102,13 @@ orbitGetXForm(OrbitalElements elements)
 	return M;
 }
 
+double
+orbitGetVectorMagnitude(glm::dvec3 v)
+{
+	return(sqrt(pow(v.x, 2) + pow(v.y, 2) + pow(v.z, 2)));
+}
+
+
 //
 // NOTE: propagate anomaly functions:
 //
diff --git a/src/orbits.h b/src/orbits.h
index 589ad55..fe63ba2 100644
--- a/src/orbits.h
+++ b/src/orbits.h
@@ -121,6 +121,8 @@ glm::dvec3 orbitGetVelocityVector(double mu, double h, double e, double theta);
 //	in column major format
 glm::dmat3 orbitGetXForm(OrbitalElements elements);
 
+double orbitGetVectorMagnitude(glm::dvec3 v);
+
 inline double
 orbitGetAngularMomentum(double p, double mu)
 {